This all-dark seabird spends most of its life at sea and breeds on remote volcanic islands. In warm waters, it typically feeds on bioluminescent fish that surface at night.
It is a small petrel with all-dark plumage.
On Vila Islet in the Azores, researchers followed breeding Bulwer’s Petrels from 2002 to 2012. They checked burrows, identified and measured adults, ringed chicks, and recorded which pairs bred. Genetic analyses included 91 adult birds.
The studied colony showed no evidence of inbreeding or a genetic bottleneck. Pairs were not formed according to genetic relatedness, body measurements, or breeding experience. Divorces were very rare, and most observed separations were considered likely to have been forced. The work combined individual records and genetic evidence to examine pair formation in a small colony.
An extinction-risk assessment has not been added yet.
Long-term records of nests and identified birds can reveal how small colonies change. The authors recommend checking whether reduced selectivity in mate choice also occurs in other small Procellariiform populations.